Carlos Pena and the Houston Astros will play their first game as an American League team today.

HOUSTON — The stars are gathering in Los Angeles, and Canada’s club could be poised for a return to past glory in the 2013 MLB season that gets underway today.

A lively trade and free agent market has fanned hopes from Toronto to major league outposts in Kansas City and Seattle, and on to the City of Angels, where the Dodgers have more than doubled their payroll.

A corresponding feeling of dread descended on fans of the New York Yankees, who suddenly stopped spending and were hit by anxieties over age and injury, and in Miami, where the Marlins dumped salaries after a poor debut season in their new ballpark.

Another ominious Florida cloud threatened MLB, which was reports linking some prominent players, including Alex Rodriguez and Ryan Braun, to an anti-aging clinic that allegedly supplied prohibited drugs.

With all that brewing, the San Francisco Giants focused on keeping their championship crew together, trusting that their pitching staff led by Matt Cain and their lineup led by Leesburg native and NL MVP Buster Posey would give them a chance at a third World Series in four years.

The Texas Rangers and Houston Astros launch the season and a new Lone Star State divisional rivalry today when they meet as American League West foes.

Houston shifted from the National League, balancing the majors with 15 teams in each league and setting up a steady diet of interleague play throughout the season.

Texas has juggled a lineup that took it into the 2010 and 2011 World Series with slugger Josh Hamilton, clubhouse leader Michael Young and power-hitting catcher Mike Napoli now gone.

RECORD SALARY: Hamilton signed a five-year contract with the Los Angeles Angels worth $125 million, joining a cast that includes three-time NL MVP Albert Pujols and reigning AL Rookie of the Year Mike Trout.

The Dodgers have spent big to battle the Giants for NL West supremacy and the Angels for their home city’s affection and cable TV ratings.

Dodgers owners, including ex-Lakers’ great Magic Johnson, worked out a new TV deal worth at least $7 billion over 25 years.

After a trade with the Boston Red Sox late last season brought in Adrian Gonzalez, Carl Crawford and Josh Beckett for $250 million in contracts, the Dodgers added free agent pitcher Zack Greinke in the offseason for $147 million.

The Dodgers have more than doubled the estimated $95 million payroll they began with last season, and in 2013 will be surpassing the Yankees’ record mark of $210 million.

The Yankees, who during the bombastic reign of late owner George Steinbrenner spent whatever it took to try and satisfy a World Series-or-bust mentality, have grown budget conscious under the regime of his sons, Hal and Hank.

Unlike the NFL, NBA and NHL, baseball does not employ a salary cap to hold down costs, instead using a luxury tax to punish owners that exceed the payroll limit.

Hit with a $19.3 million penalty this offseason as the only team taxed, and with stiffer penalties kicking in next season, the Yankees were striving to stay under the $189 million threshold for 2014 rather than shopping for big bats.

They let home run hitters Nick Swisher, Raul Ibanez and catcher Russell Martin leave via free agency. Spring injuries to Mark Teixeira and Curtis Granderson added to mounting concerns about aging stars Alex Rodriguez, out at least until mid-season, and Derek Jeter, coming back from a broken ankle.

While getting older may be a curse for the Yankees, it could turn the Washington Nationals into champions.

OVERTAXING STRASBURG: The NL East-winning Nationals, who won an MLB-best 98 games last season, caused a stir when they shut down young pitching ace Stephen Strasburg (15-6) in early September over worries about overtaxing his arm.

Strasburg was missed in the playoffs as Washington lost to the St. Louis Cardinals, but his restrictions have been removed and Washington could be primed to bring the first World Series crown to the U.S. capital in 89 years.

Atlanta, perennial NL East contenders, added the Upton brothers, Justin and B.J., over the offseason to add punch to its attack.

Toronto restructured its roster, livening up the offense with shortstop Jose Reyes and the rotation with Josh Johnson and Mark Buehrle as part of a blockbuster trade with Miami.

A deal with the Mets brought the Blue Jays Cy Young knuckleballer R.A. Dickey in their bid to supplant the Yanks in the AL East and recapture the glory of their 1992-93 World Series triumphs.

In the AL Central, the Royals added pitching to their emerging offense by dealing prospect Wil Myers to Tampa Bay for starters James Shields and Wade Davis, though reigning AL champion Detroit still look to be the class of the division.

The Cincinnati Reds, who won 97 games in 2012, remain a solid favorite in the NL Central with the consistent St. Louis Cardinals always a threat.

The AL West, which includes the pitching-rich, division-winning Oakland A’s, Rangers and Angels, could grow even more competitive with Seattle beefing up on offense after adding Kendrys Morales and Mike Morse.